The goal of this study is to build a VISN-wide agent-based simulation model of MRSA transmission and control to compare the effectiveness and cost-effectiveness of various MRSA control strategies. Our specific objectives are to: (a) extend an existing hospital-level MRSA agent-based simulation model to include physician teams and behaviors, and expand into a VISN-wide model that includes VA community living centers; (b) use the extended model to compare the costs, impacts, and cost-effectiveness of MRSA infection control strategies, alone or in combination, and to assess the impact of varying levels of provider team uptake behaviors on strategy effectiveness; and (c) develop and disseminate a web-based version to be used by decision-makers at local, VISN, and national levels when making clinical and economic decisions about MRSA control strategies. We will utilize existing systematic reviews, analyses of VA data, and findings including ethnographic observations from our other CREATE Projects to establish estimates of the key parameters needed for the model, such as: MRSA surveillance and prevalence data; duration, nature and frequency of healthcare worker visits to patient rooms in acute care and in VA CLCs; data on physician team attributes and behavioral measures and impact on patient outcomes; and costs associated with MRSA infection and various intervention components. These results will be incorporated into the simulation, which will then be used to assess the various strategies and factors that impact MRSA transmission through a series of simulation experiments. Traditional quantitative epidemiologic methods will be used to analyze simulation results, with a focus on MRSA incidence and transmission rates as outcomes. Dynamic cost-benefit analyses will be performed by projecting MRSA incidence rates and costs under the various alternative policies. The model will then be converted to a web-based version, with a simple, graphical interface, to be deployed via the VA intranet to provide real-time facility- or VISN-specific estimated benefits, costs, and cost-effectiveness of the various MRSA control strategies.